This invention relates generally to cords and ropes, and more particularly to an elasticized double wall tubular cord which is used in commercial settings, such as for strapping, safety ropes and the like.
Elasticized cords useful for commercial and household purposes have been available for many years. Reference can be made to U.S. Pat. Nos. 478,076 to Asten, and 4,745,883 to Baggetta, these patents being representative of the prior art in this area. The patent to Asten discloses a strip of inelastic material which is stitched to completely surround a strip of elastic material. Although the specific manner in which the inelastic strip and the elastic strip are attached is not revealed in Asten, it is apparent that the elastic strip is attached to the inelastic strip in stretched condition.
The Baggetta patent discloses an inelastic tube having an elastic strip disposed therein which is attached to the tube in stretched condition by stitches. More specifically, a strip of cloth is formed into a tube by securing longitudinally extending sides of the cloth together by stitching. The elastic strip is inserted into the cloth tube and secured at its longitudinal ends with stitching. Next, the elastic strip is stretched until its length is equal to the length of the tube and the elastic strip is stitched to the tube along their entire length while taught.
Other patents of interest in this area are U.S. Pat. Nos. 1,920,106 to Reichert, 3,441,005 to Fink, 4,426,908 to Ullmann, 4,777,784 to Ferguson, 4,993,366 to Sager, and 5,308,101 to Monty.
One disadvantage associated with the prior art elasticized cords, including those found in Asten and Baggetta, is that they are difficult to manufacture since two separate and distinct fabric strips must be secured together. This oftentimes requires a separate and distinct machine to sew the two fabrics together. There is presently a need for an elasticized cord which is easier and more cost-efficient to manufacture than the prior art cords.
The present invention is directed to an elasticized double wall tubular cord comprising an outer wall fabricated from a tube of woven material that is comprised of heavy duty, inelastic yarns, and an inner wall fabricated from a tube of woven material that is comprised partially of heavy duty, inelastic yarns and partially of elastic fibers woven therein. The inner tube of woven material is stretchable lengthwise and attached to the outer tube of woven material along respective long edges thereof when in stretched condition. The arrangement is such that when the inner tube of the tubular cord is in relaxed condition, the outer tube is compressed due to the compression force of the elastic fibers of the inner tube for shortening the tubular cord.
Accordingly, among the several objects of the present invention are the provision of an elasticized double wall tubular cord fabricated from two tubes of woven material which is sturdy in construction and useful for commercial purposes, such as for strapping items in place, safety ropes and the like; the provision of such a double wall tubular cord which is economical to manufacture; and the provision of such a double wall tubular cord which can be manufactured from existing weaving equipment.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.